


Hell knows no fury like a plotting sister

by BellaP



Series: It's all about genetics [3]
Category: Percy Jackson and the Olympians - Rick Riordan, Teen Wolf (TV)
Genre: F/M, Humor, M/M, Pre-Slash, Romance, Swearing
Language: English
Status: Completed
Published: 2012-08-15
Updated: 2012-08-15
Packaged: 2017-11-12 05:22:59
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,429
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/487164
Author URL: https://archiveofourown.org/users/BellaP/pseuds/BellaP
Summary: <blockquote class="userstuff">
              <p>When Stiles first met Cassidy 'Cass' Carlson, she was putting fire on her twin brother's ass. So he was right to be afraid for Derek. Very afraid.</p>
            </blockquote>





	Hell knows no fury like a plotting sister

**Author's Note:**

> Obviously that Teen Wolf doesn't belong to me. If it did, Derek and Stiles would be a thing a long time ago.  
> Also, English isn't my first language. So sorry for the grammatical mistakes.

When Stiles first met Cassidy 'Cass' Carlson, she was putting fire on her twin brother's ass. I mean, real fire. That one it burns and leave marks. Stiles, an impressionable child and recently gifted with the knowledge that he was a demigod, at that time screamed and threw the first thing that he found to put the fire away. The first thing being Dionysus' coke that he grabbed from the god's hands himself. Stiles act rendered half of the camp speechless and got to himself a person to bully him in all the summers that he spent in the half-blood camp. So, Mr. Harris and his offenses to his intelligence? Piece of cake to deal with when Stiles had to go against a god every freaking summer.

But nothing, and I say _nothing_ , is ever comparable to what is Cass with a plot in mind and a thirst to do justice with her own bare hands. Okay, Stiles was exaggerating again, or as always and maybe he was more Apollo's son with all his dramatic talent than Athena's. But anyway, when Stiles called his sister asking for help and had as an answer something like: “Hang on little brother, because when I'm finished that wolf will jump as high as you ask him to.” he knew that something big was about to happen. Something that would make him get what he wanted or scar poor Derek for life. 

So it wasn't a big surprise when Monday came and the last bell ringed across the Beacon Hills High School's facilities, making everybody scurry to leave the hell out of there and with some students stopping to look at the strange girl sitting on the hood of a black 1969 Camaro wearing torn jeans, an old t-shirt, old All Stars, with long black and wavy hair and storm gray eyes. Stiles eyes almost went out of its socks when he opened the school's door to see the chubby and small form of his one year older sister waiting for him in the parking lot. Some cheerleaders passed by her, giving to Cass a stink eye because of her out of standard anorexic supermodel body, messy hair, faded clothes and chipped nail polish. Some jocks looked longer at her because Cass wasn't the futile teenager boy's dream girl, but there was something in her intense eyes and too pretty face that caught anyone's attention.

“Look longer and your eyes will fall out of your socks pretty boy.” She said to one of the jocks, blinking an eye to him and making the boy blush and stammer something before he turned and left under his friend's laughs. “And just for you to know...” She pointed at the cheerleaders. “I'm not over weighted. I only have more of me to be loved and my boyfriend like very much.” And man Stiles wanted to laugh when he heard Cass' sharp tongue dismissing the girls who were still giving her the stink eyes. They probably didn't believe the boyfriend story, what would bite them back in the ass if one day they meet him. Joshua Spencer was a dream come true for any girl. Being Apollo's son usually makes the boys a teenager girl's dream. And Joshua proved many times that he liked his girl with a good brain, not a good body.

“Stiles!” Cass screamed when she saw the boy on the school's entry stairs, jumping out off the car and running to him. Stiles braced himself because Cass could be a petite woman, but she was the best wrestling fighter in the Athena's cabin, so she knew how to take down a grown up man. So a scrawny teen like him would be nothing for her. 

“Dude, who is she?” Stiles turned, while Cass was crushing him in her hug, to look at Scott's confused expression. 

“Dude...” She mocked Scott's tone. “I'm his sister.” McCall's expression became more confused and Stiles worried that Cass with her big mouth and no sense attitude fried his best friend's brain. Scott's mind could only process one thing at the time, so that was the reason (at least it was the conclusion that Stiles reached after he was dumped for the ninth time by Scott for Allison) that his friend was so obsessed with the hunter's daughter. 

“You don't have a sister.” Was Scott's answer and Stiles rolled his eyes. He had a lot of sisters and brothers, but the other boy didn't know that. It would be a long story to be told and if Derek – the impenetrable brick wall – reacted the way he did, Scott would freak out of proportion with the truth. 

“If you look closer, they do look alike. Both are nerdy and losers.” Cass storm gray eyes zeroed on Lydia who lately was walking with their group because after Peter's attack and her brief 'vacation' in the hospital, people were all avoiding her. It didn't help that recently she had a break down in the middle of the class. 

“Who the fuck are you?” Cass let go of Stiles to glare at Lydia. Her language already made Athena herself visit the half-blood camp to reprimand her daughter. The goddess couldn't understand how Cass, being the daughter of a brilliant college professor and researcher, could be so... Cass. There wasn't any other definition that matched the girl. Lydia returned Cass' glare and Stiles had the sensation that they were measuring each other's worth. After a minute with the two girls looking at each other, Cass seemed to found what she was looking for and gave to Lydia a big smile. “So, are you aware of Stiles' situation?”

“The one that he has an ex-murder accused with a puppy love for him and who is hot as hell, what makes me think how a loser like Stiles was able to catch that sin on legs attention?”

“I like you redhead. So you gonna help me with my plan.” Lydia's green eyes glowed like a damn Christmas' tree when she heard what Cass said and Stiles gulped. His sister was crazy and Lydia always has been his private goddess. If the Olympus was opening a spot for new deities, Lydia would be the perfect candidate. She was a mix of Aphrodite's beauty, Artemis' fierceness and Athena's intelligence. She was a force to be reckoned. And now she was joining forces with Cass. The world was about to end. 

“What do you have in mind?” Lydia intertwined her arm with Cass', guiding the shorter girl to the 1969 Camaro, with both starting to whisper under their breath something or another. 

“See you later Stiles!” Cass screamed over her shoulder at the same time she opened the car's door and Lydia and her got inside the vehicle that left the parking lot with a screech of its tires. 

“But... Dude...” Stiles turned again to see that Scott still had his standard confused expression. “You don't have a sister.” The demigod rolled his eyes and patted his best friend's shoulder in a comforting gesture. If Cass presence had broke Scott, Stiles was afraid of what her plan would do with Derek. Scared, he got his cell phone out of his backpack and rapidly dialed his sister number. 

“You better get me a still hot on legs sour wolf Cassidy, not a mass of babbling incoherent things.” Because he knew his sister well enough to know that after the Cassidy storm has passed, nothing would be left behind to tell the story. The girl only answer was a long laugh. 

“Don't worry little brother. I'll not break him... much.”

“Cassidy!”

“But I have to know...” A pause and Stiles' heart jumped in his chest because of her serious tone. “Would you like me to give him to you in a collar or in a cage?” She laughed again and he could hear Lydia's laugh echoing with his sister's. 

“Fuck you!” He screamed to the phone and hang up on her face. 

“Dude, seriously, sister?”

“Really Scott?” Stiles snorted. “Look! There is Allison!” He pointed to somewhere behind the other boy and the reaction was instantly. Scott's eyes went large and he turned with a big grin on his face, like a damn puppy who just found out that his favorite person was back in the city.

“Where?” Stiles knew he was being cruel, but it was the only way he found to escape Scott's inquiry. He had other things to worry right now, like the fact that Derek was so screwed and it wasn't even in a good way. Damn. 

 


End file.
